You can eat 2 year old frozen bread as long as there is no mold on it or signs of spoilage.
If the bread just has some freezer burn then it's safe to eat but the 2 year old bread will not taste as good as fresh but as long as it has not actually gone bad it will not hurt you to eat the 2 year old frozen bread.
Toasting frozen bread is safe and there's no need to thaw the frozen bread before toasting it.
However toasting frozen bread can take a bit longer to toast than thawed or fresh bread.
You can place the frozen bread directly into the toast, toaster oven, pan, oven etc and it will toast just fine and be safe to do so.
Just make sure that the frozen bread has no large ice crystals on the bread before toasting.
If making sandwiches from frozen bread you should allow it to sit on the counter for awhile to thaw some.
But when just making toast the frozen bread can be toasted from frozen.
I put frozen breast in my toaster all the time and the toaster thaws it out and cooks it just fine.